3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "libavutil/bprint.h"
25 #include "libavutil/imgutils.h"
27 #include "bytestream.h"
34 * - add 16 bit depth support
39 typedef struct PNGDecContext {
41 AVCodecContext *avctx;
44 ThreadFrame last_picture;
60 uint32_t palette[256];
68 int crow_size; /* compressed row size (include filter type) */
69 int row_size; /* decompressed row size */
70 int pass_row_size; /* decompress row size of the current pass */
75 /* Mask to determine which pixels are valid in a pass */
76 static const uint8_t png_pass_mask[NB_PASSES] = {
77 0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
80 /* Mask to determine which y pixels can be written in a pass */
81 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
82 0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
85 /* Mask to determine which pixels to overwrite while displaying */
86 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
87 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
90 /* NOTE: we try to construct a good looking image at each pass. width
91 is the original image width. We also do pixel format conversion at
93 static void png_put_interlaced_row(uint8_t *dst, int width,
94 int bits_per_pixel, int pass,
95 int color_type, const uint8_t *src)
97 int x, mask, dsp_mask, j, src_x, b, bpp;
101 mask = png_pass_mask[pass];
102 dsp_mask = png_pass_dsp_mask[pass];
104 switch (bits_per_pixel) {
107 for (x = 0; x < width; x++) {
109 if ((dsp_mask << j) & 0x80) {
110 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
111 dst[x >> 3] &= 0xFF7F>>j;
112 dst[x >> 3] |= b << (7 - j);
114 if ((mask << j) & 0x80)
120 for (x = 0; x < width; x++) {
121 int j2 = 2 * (x & 3);
123 if ((dsp_mask << j) & 0x80) {
124 b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
125 dst[x >> 2] &= 0xFF3F>>j2;
126 dst[x >> 2] |= b << (6 - j2);
128 if ((mask << j) & 0x80)
134 for (x = 0; x < width; x++) {
137 if ((dsp_mask << j) & 0x80) {
138 b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
139 dst[x >> 1] &= 0xFF0F>>j2;
140 dst[x >> 1] |= b << (4 - j2);
142 if ((mask << j) & 0x80)
147 bpp = bits_per_pixel >> 3;
150 for (x = 0; x < width; x++) {
152 if ((dsp_mask << j) & 0x80) {
156 if ((mask << j) & 0x80)
163 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
166 for (i = 0; i < w; i++) {
167 int a, b, c, p, pa, pb, pc;
180 if (pa <= pb && pa <= pc)
190 #define UNROLL1(bpp, op) {\
192 if(bpp >= 2) g = dst[1];\
193 if(bpp >= 3) b = dst[2];\
194 if(bpp >= 4) a = dst[3];\
195 for(; i <= size - bpp; i+=bpp) {\
196 dst[i+0] = r = op(r, src[i+0], last[i+0]);\
197 if(bpp == 1) continue;\
198 dst[i+1] = g = op(g, src[i+1], last[i+1]);\
199 if(bpp == 2) continue;\
200 dst[i+2] = b = op(b, src[i+2], last[i+2]);\
201 if(bpp == 3) continue;\
202 dst[i+3] = a = op(a, src[i+3], last[i+3]);\
206 #define UNROLL_FILTER(op)\
207 if(bpp == 1) UNROLL1(1, op)\
208 else if(bpp == 2) UNROLL1(2, op)\
209 else if(bpp == 3) UNROLL1(3, op)\
210 else if(bpp == 4) UNROLL1(4, op)\
211 for (; i < size; i++) {\
212 dst[i] = op(dst[i-bpp], src[i], last[i]);\
215 /* NOTE: 'dst' can be equal to 'last' */
216 static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
217 uint8_t *src, uint8_t *last, int size, int bpp)
219 int i, p, r, g, b, a;
221 switch (filter_type) {
222 case PNG_FILTER_VALUE_NONE:
223 memcpy(dst, src, size);
225 case PNG_FILTER_VALUE_SUB:
226 for (i = 0; i < bpp; i++) {
231 for (; i < size; i += bpp) {
232 int s = *(int*)(src + i);
233 p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
234 *(int*)(dst + i) = p;
237 #define OP_SUB(x,s,l) x+s
238 UNROLL_FILTER(OP_SUB);
241 case PNG_FILTER_VALUE_UP:
242 dsp->add_bytes_l2(dst, src, last, size);
244 case PNG_FILTER_VALUE_AVG:
245 for (i = 0; i < bpp; i++) {
249 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
250 UNROLL_FILTER(OP_AVG);
252 case PNG_FILTER_VALUE_PAETH:
253 for (i = 0; i < bpp; i++) {
257 if (bpp > 2 && size > 4) {
258 // would write off the end of the array if we let it process the last pixel with bpp=3
259 int w = bpp == 4 ? size : size - 3;
260 dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
263 ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
268 /* This used to be called "deloco" in FFmpeg
269 * and is actually an inverse reversible colorspace transformation */
270 #define YUV2RGB(NAME, TYPE) \
271 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
274 for (i = 0; i < size; i += 3 + alpha) { \
281 YUV2RGB(rgb8, uint8_t)
282 YUV2RGB(rgb16, uint16_t)
284 /* process exactly one decompressed row */
285 static void png_handle_row(PNGDecContext *s)
287 uint8_t *ptr, *last_row;
290 if (!s->interlace_type) {
291 ptr = s->image_buf + s->image_linesize * s->y;
293 last_row = s->last_row;
295 last_row = ptr - s->image_linesize;
297 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
298 last_row, s->row_size, s->bpp);
299 /* loco lags by 1 row so that it doesn't interfere with top prediction */
300 if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
301 if (s->bit_depth == 16) {
302 deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
303 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
305 deloco_rgb8(ptr - s->image_linesize, s->row_size,
306 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
310 if (s->y == s->height) {
311 s->state |= PNG_ALLIMAGE;
312 if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
313 if (s->bit_depth == 16) {
314 deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
315 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
317 deloco_rgb8(ptr, s->row_size,
318 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
325 ptr = s->image_buf + s->image_linesize * s->y;
326 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
327 /* if we already read one row, it is time to stop to
328 wait for the next one */
331 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
332 s->last_row, s->pass_row_size, s->bpp);
333 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
336 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
337 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
338 s->color_type, s->last_row);
341 if (s->y == s->height) {
342 memset(s->last_row, 0, s->row_size);
344 if (s->pass == NB_PASSES - 1) {
345 s->state |= PNG_ALLIMAGE;
350 s->pass_row_size = ff_png_pass_row_size(s->pass,
353 s->crow_size = s->pass_row_size + 1;
354 if (s->pass_row_size != 0)
356 /* skip pass if empty row */
365 static int png_decode_idat(PNGDecContext *s, int length)
368 s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
369 s->zstream.next_in = (unsigned char *)s->gb.buffer;
370 bytestream2_skip(&s->gb, length);
372 /* decode one line if possible */
373 while (s->zstream.avail_in > 0) {
374 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
375 if (ret != Z_OK && ret != Z_STREAM_END) {
376 av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
377 return AVERROR_EXTERNAL;
379 if (s->zstream.avail_out == 0) {
380 if (!(s->state & PNG_ALLIMAGE)) {
383 s->zstream.avail_out = s->crow_size;
384 s->zstream.next_out = s->crow_buf;
390 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
391 const uint8_t *data_end)
398 zstream.zalloc = ff_png_zalloc;
399 zstream.zfree = ff_png_zfree;
400 zstream.opaque = NULL;
401 if (inflateInit(&zstream) != Z_OK)
402 return AVERROR_EXTERNAL;
403 zstream.next_in = (unsigned char *)data;
404 zstream.avail_in = data_end - data;
405 av_bprint_init(bp, 0, -1);
407 while (zstream.avail_in > 0) {
408 av_bprint_get_buffer(bp, 1, &buf, &buf_size);
410 ret = AVERROR(ENOMEM);
413 zstream.next_out = buf;
414 zstream.avail_out = buf_size;
415 ret = inflate(&zstream, Z_PARTIAL_FLUSH);
416 if (ret != Z_OK && ret != Z_STREAM_END) {
417 ret = AVERROR_EXTERNAL;
420 bp->len += zstream.next_out - buf;
421 if (ret == Z_STREAM_END)
424 inflateEnd(&zstream);
425 bp->str[bp->len] = 0;
429 inflateEnd(&zstream);
430 av_bprint_finalize(bp, NULL);
434 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
439 for (i = 0; i < size_in; i++)
440 extra += in[i] >= 0x80;
441 if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
443 q = out = av_malloc(size_in + extra + 1);
446 for (i = 0; i < size_in; i++) {
448 *(q++) = 0xC0 | (in[i] >> 6);
449 *(q++) = 0x80 | (in[i] & 0x3F);
458 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
462 const uint8_t *data = s->gb.buffer;
463 const uint8_t *data_end = data + length;
464 const uint8_t *keyword = data;
465 const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
466 uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
471 return AVERROR_INVALIDDATA;
472 data = keyword_end + 1;
475 if (data == data_end)
476 return AVERROR_INVALIDDATA;
479 return AVERROR_INVALIDDATA;
480 if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
483 av_bprint_finalize(&bp, (char **)&text);
485 return AVERROR(ENOMEM);
487 text = (uint8_t *)data;
488 text_len = data_end - text;
491 kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
492 txt_utf8 = iso88591_to_utf8(text, text_len);
495 if (!(kw_utf8 && txt_utf8)) {
498 return AVERROR(ENOMEM);
501 av_dict_set(dict, kw_utf8, txt_utf8,
502 AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
506 static int decode_frame(AVCodecContext *avctx,
507 void *data, int *got_frame,
510 PNGDecContext * const s = avctx->priv_data;
511 const uint8_t *buf = avpkt->data;
512 int buf_size = avpkt->size;
514 AVDictionary *metadata = NULL;
515 uint32_t tag, length;
519 ff_thread_release_buffer(avctx, &s->last_picture);
520 FFSWAP(ThreadFrame, s->picture, s->last_picture);
523 bytestream2_init(&s->gb, buf, buf_size);
525 /* check signature */
526 sig = bytestream2_get_be64(&s->gb);
529 av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
530 return AVERROR_INVALIDDATA;
536 s->zstream.zalloc = ff_png_zalloc;
537 s->zstream.zfree = ff_png_zfree;
538 s->zstream.opaque = NULL;
539 ret = inflateInit(&s->zstream);
541 av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
542 return AVERROR_EXTERNAL;
545 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
546 av_log(avctx, AV_LOG_ERROR, "No bytes left\n");
550 length = bytestream2_get_be32(&s->gb);
551 if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) {
552 av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
555 tag = bytestream2_get_le32(&s->gb);
556 if (avctx->debug & FF_DEBUG_STARTCODE)
557 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
560 ((tag >> 16) & 0xff),
561 ((tag >> 24) & 0xff), length);
563 case MKTAG('I', 'H', 'D', 'R'):
566 s->width = bytestream2_get_be32(&s->gb);
567 s->height = bytestream2_get_be32(&s->gb);
568 if (av_image_check_size(s->width, s->height, 0, avctx)) {
569 s->width = s->height = 0;
570 av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
573 s->bit_depth = bytestream2_get_byte(&s->gb);
574 s->color_type = bytestream2_get_byte(&s->gb);
575 s->compression_type = bytestream2_get_byte(&s->gb);
576 s->filter_type = bytestream2_get_byte(&s->gb);
577 s->interlace_type = bytestream2_get_byte(&s->gb);
578 bytestream2_skip(&s->gb, 4); /* crc */
579 s->state |= PNG_IHDR;
580 if (avctx->debug & FF_DEBUG_PICT_INFO)
581 av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
582 "compression_type=%d filter_type=%d interlace_type=%d\n",
583 s->width, s->height, s->bit_depth, s->color_type,
584 s->compression_type, s->filter_type, s->interlace_type);
586 case MKTAG('p', 'H', 'Y', 's'):
587 if (s->state & PNG_IDAT) {
588 av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
591 avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
592 avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
593 if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
594 avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
595 bytestream2_skip(&s->gb, 1); /* unit specifier */
596 bytestream2_skip(&s->gb, 4); /* crc */
598 case MKTAG('I', 'D', 'A', 'T'):
599 if (!(s->state & PNG_IHDR)) {
600 av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
603 if (!(s->state & PNG_IDAT)) {
604 /* init image info */
605 avctx->width = s->width;
606 avctx->height = s->height;
608 s->channels = ff_png_get_nb_channels(s->color_type);
609 s->bits_per_pixel = s->bit_depth * s->channels;
610 s->bpp = (s->bits_per_pixel + 7) >> 3;
611 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
613 if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
614 s->color_type == PNG_COLOR_TYPE_RGB) {
615 avctx->pix_fmt = AV_PIX_FMT_RGB24;
616 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
617 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
618 avctx->pix_fmt = AV_PIX_FMT_RGBA;
619 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
620 s->color_type == PNG_COLOR_TYPE_GRAY) {
621 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
622 } else if (s->bit_depth == 16 &&
623 s->color_type == PNG_COLOR_TYPE_GRAY) {
624 avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
625 } else if (s->bit_depth == 16 &&
626 s->color_type == PNG_COLOR_TYPE_RGB) {
627 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
628 } else if (s->bit_depth == 16 &&
629 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
630 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
631 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
632 s->color_type == PNG_COLOR_TYPE_PALETTE) {
633 avctx->pix_fmt = AV_PIX_FMT_PAL8;
634 } else if (s->bit_depth == 1) {
635 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
636 } else if (s->bit_depth == 8 &&
637 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
638 avctx->pix_fmt = AV_PIX_FMT_Y400A;
640 av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
641 "and color type %d\n",
642 s->bit_depth, s->color_type);
646 if (ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF) < 0)
648 ff_thread_finish_setup(avctx);
650 p->pict_type = AV_PICTURE_TYPE_I;
652 p->interlaced_frame = !!s->interlace_type;
654 /* compute the compressed row size */
655 if (!s->interlace_type) {
656 s->crow_size = s->row_size + 1;
659 s->pass_row_size = ff_png_pass_row_size(s->pass,
662 s->crow_size = s->pass_row_size + 1;
664 av_dlog(avctx, "row_size=%d crow_size =%d\n",
665 s->row_size, s->crow_size);
666 s->image_buf = p->data[0];
667 s->image_linesize = p->linesize[0];
668 /* copy the palette if needed */
669 if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
670 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
671 /* empty row is used if differencing to the first row */
672 av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
675 if (s->interlace_type ||
676 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
677 s->tmp_row = av_malloc(s->row_size);
682 av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
686 /* we want crow_buf+1 to be 16-byte aligned */
687 s->crow_buf = s->buffer + 15;
688 s->zstream.avail_out = s->crow_size;
689 s->zstream.next_out = s->crow_buf;
691 s->state |= PNG_IDAT;
692 if (png_decode_idat(s, length) < 0)
694 bytestream2_skip(&s->gb, 4); /* crc */
696 case MKTAG('P', 'L', 'T', 'E'):
700 if ((length % 3) != 0 || length > 256 * 3)
702 /* read the palette */
704 for (i = 0; i < n; i++) {
705 r = bytestream2_get_byte(&s->gb);
706 g = bytestream2_get_byte(&s->gb);
707 b = bytestream2_get_byte(&s->gb);
708 s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
710 for (; i < 256; i++) {
711 s->palette[i] = (0xFFU << 24);
713 s->state |= PNG_PLTE;
714 bytestream2_skip(&s->gb, 4); /* crc */
717 case MKTAG('t', 'R', 'N', 'S'):
721 /* read the transparency. XXX: Only palette mode supported */
722 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
724 !(s->state & PNG_PLTE))
726 for (i = 0; i < length; i++) {
727 v = bytestream2_get_byte(&s->gb);
728 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
730 bytestream2_skip(&s->gb, 4); /* crc */
733 case MKTAG('t', 'E', 'X', 't'):
734 if (decode_text_chunk(s, length, 0, &metadata) < 0)
735 av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
736 bytestream2_skip(&s->gb, length + 4);
738 case MKTAG('z', 'T', 'X', 't'):
739 if (decode_text_chunk(s, length, 1, &metadata) < 0)
740 av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
741 bytestream2_skip(&s->gb, length + 4);
743 case MKTAG('I', 'E', 'N', 'D'):
744 if (!(s->state & PNG_ALLIMAGE))
745 av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
746 if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
749 bytestream2_skip(&s->gb, 4); /* crc */
754 bytestream2_skip(&s->gb, length + 4);
760 if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){
762 uint8_t *pd = p->data[0];
763 for (j = 0; j < s->height; j++) {
765 for (k = 7; k >= 1; k--)
766 if ((s->width&7) >= k)
767 pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
768 for (i--; i >= 0; i--) {
769 pd[8*i + 7]= pd[i] & 1;
770 pd[8*i + 6]= (pd[i]>>1) & 1;
771 pd[8*i + 5]= (pd[i]>>2) & 1;
772 pd[8*i + 4]= (pd[i]>>3) & 1;
773 pd[8*i + 3]= (pd[i]>>4) & 1;
774 pd[8*i + 2]= (pd[i]>>5) & 1;
775 pd[8*i + 1]= (pd[i]>>6) & 1;
776 pd[8*i + 0]= pd[i]>>7;
778 pd += s->image_linesize;
781 if (s->bits_per_pixel == 2){
783 uint8_t *pd = p->data[0];
784 for (j = 0; j < s->height; j++) {
786 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
787 if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
788 if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
789 if ((s->width&3) >= 1) pd[4*i + 0]= pd[i] >> 6;
790 for (i--; i >= 0; i--) {
791 pd[4*i + 3]= pd[i] & 3;
792 pd[4*i + 2]= (pd[i]>>2) & 3;
793 pd[4*i + 1]= (pd[i]>>4) & 3;
794 pd[4*i + 0]= pd[i]>>6;
797 if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
798 if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
799 if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6 )*0x55;
800 for (i--; i >= 0; i--) {
801 pd[4*i + 3]= ( pd[i] & 3)*0x55;
802 pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
803 pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
804 pd[4*i + 0]= ( pd[i]>>6 )*0x55;
807 pd += s->image_linesize;
810 if (s->bits_per_pixel == 4){
812 uint8_t *pd = p->data[0];
813 for (j = 0; j < s->height; j++) {
815 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
816 if (s->width&1) pd[2*i+0]= pd[i]>>4;
817 for (i--; i >= 0; i--) {
818 pd[2*i + 1] = pd[i] & 15;
819 pd[2*i + 0] = pd[i] >> 4;
822 if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
823 for (i--; i >= 0; i--) {
824 pd[2*i + 1] = (pd[i] & 15) * 0x11;
825 pd[2*i + 0] = (pd[i] >> 4) * 0x11;
828 pd += s->image_linesize;
832 /* handle p-frames only if a predecessor frame is available */
833 if (s->last_picture.f->data[0]) {
834 if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
835 && s->last_picture.f->width == p->width
836 && s->last_picture.f->height== p->height
837 && s->last_picture.f->format== p->format
840 uint8_t *pd = p->data[0];
841 uint8_t *pd_last = s->last_picture.f->data[0];
843 ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
844 for (j = 0; j < s->height; j++) {
845 for (i = 0; i < s->width * s->bpp; i++) {
848 pd += s->image_linesize;
849 pd_last += s->image_linesize;
853 ff_thread_report_progress(&s->picture, INT_MAX, 0);
855 av_frame_set_metadata(p, metadata);
858 if ((ret = av_frame_ref(data, s->picture.f)) < 0)
863 ret = bytestream2_tell(&s->gb);
865 inflateEnd(&s->zstream);
867 av_freep(&s->tmp_row);
870 av_dict_free(&metadata);
871 ff_thread_report_progress(&s->picture, INT_MAX, 0);
872 ret = AVERROR_INVALIDDATA;
876 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
878 PNGDecContext *psrc = src->priv_data;
879 PNGDecContext *pdst = dst->priv_data;
884 ff_thread_release_buffer(dst, &pdst->picture);
885 if (psrc->picture.f->data[0])
886 return ff_thread_ref_frame(&pdst->picture, &psrc->picture);
891 static av_cold int png_dec_init(AVCodecContext *avctx)
893 PNGDecContext *s = avctx->priv_data;
896 s->last_picture.f = av_frame_alloc();
897 s->picture.f = av_frame_alloc();
898 if (!s->last_picture.f || !s->picture.f)
899 return AVERROR(ENOMEM);
901 if (!avctx->internal->is_copy) {
902 avctx->internal->allocate_progress = 1;
903 ff_pngdsp_init(&s->dsp);
909 static av_cold int png_dec_end(AVCodecContext *avctx)
911 PNGDecContext *s = avctx->priv_data;
913 ff_thread_release_buffer(avctx, &s->last_picture);
914 av_frame_free(&s->last_picture.f);
915 ff_thread_release_buffer(avctx, &s->picture);
916 av_frame_free(&s->picture.f);
917 av_freep(&s->buffer);
919 av_freep(&s->last_row);
920 s->last_row_size = 0;
925 AVCodec ff_png_decoder = {
927 .type = AVMEDIA_TYPE_VIDEO,
928 .id = AV_CODEC_ID_PNG,
929 .priv_data_size = sizeof(PNGDecContext),
930 .init = png_dec_init,
931 .close = png_dec_end,
932 .decode = decode_frame,
933 .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
934 .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
935 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
936 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),